Shoe construction to provide built-in shock absorber and reduce excessive heel wear

ABSTRACT

An improved shoe construction is disclosed wherein the top surface of the inner sole has a local excavation in its posterolateral aspect to accommodate the calcaneal projection. The local excavation can be filled with a resilient material such as rubber which can be flush with the top surface of the inner sole over the excavated area or project thereabove.

United States Patent 1191 Schenker SHOE CONSTRUCTION TO PROVIDE BUILT-IN SHOCK ABSORBER AND REDUCE EXCESSIVE HEEL WEAR Inventor: Abraham Wiltse Schenker, 303 66th St., New York, NY. 10023 Filed: Sept. 21, 1973 Appl. No.: 399,649

US. Cl. 36/37 Int. Cl A43b 31/32 Field Of Search 36/35 R, 37, 71, 43

References Cited UNITED STATES PATENTS 6/1929 Schaff 36/37 1 Sept. 10, 1974 1,945,780 2/1934. Johnson 36/37 3,220,123 11/1965 Couture 36/35R Primary Examiner-Patrick D. Lawson Attorney, Agent, or FirmBurgess, Dinklage & Sprung [5 7] ABSTRACT An improved shoe construction is disclosed wherein the top surface of the inner sole has a local excavation in its postero-lateral aspect to accommodate the calcaneal projection. The local excavation can be filled with a resilient material such as rubber which can be flush with the top surface of the inner sole over the excavated area or project thereabove.

9 Claims, 9 Drawing Figures a I i 15 14% A 1 7 W/A SHOE CONSTRUCTION TO PROVIDE BUILT-IN SHOCK ABSORBER AND REDUCE EXCESSIVE HEEL WEAR BACKGROUND This invention relates to an improved shoe construc tion capable of accommodating normal walking movements from the standpoint of dynamic pressure in its relation to shock absorption. Moreover, this invention relates to a shoe construction wherein wear in its postero-lateral aspect is considerably minimized.

One of the commonest complaints or symptoms encountered in health and disease is fatigue. Even in good physical health the causes of fatigue are numerous and the literature is replete with research in this field. It is interesting to note, however, that in all of these studies mention is rarely made of fatigue inherent in the shoes we wear. I am not referring to the exotic design of fashionable or stylish shoes for the ladies but rather to the conventional shoes worn by most people throughout the civilized world.

As a physician whose chief interest has resided in the physical rehabilitation of the neuromuscular system and more particularly to the mechanics of locomotion, my attention has been pinpointed to the asymmetry of the vertical axis through the center of the knee joint and the vertical axis through the calcaneal tuberosity. The latter is the first anatomical structure to land on the ground at the start of ambulation, whether walking, running or jumping. This sudden thrust together with the asymmetry of the aforementioned axes tend to produce a shock which is transmitted throughout the skeletal system with each propulsive movement forward. The conventional shoe provides no means of preventing such transmitted shock. My invention is designed to provide a built-in shock absorber into the shoe itself, the modification involved being extremely simple.

Further, it is a common observation that in normal walking the heels of both shoes have a tendency to wear excessively in their postero-lateral aspects. To a much lesser extent the lateral aspects of the soles of the shoes also show some wear. Depending upon the weight of the individual and the nature of his gait, the amount of wear may be relatively slight or excessively heavy. But nearly always, the wear appears as an oblique area bounded by the outer-backward aspects of the shoe. Furthermore, concurrent with such rapid wear on the heels there is usually relatively little wear on the sole of the shoe which is in a symmetrical pattern more or less but with a definite tendency toward the outer aspects of the sole.

The heel repair industry is huge and the cost of replacing worn heels runs into the many millions of dollars yearly. Moreover, the rubber heels used as a replacement are in most instances and probably deliberately, of such cheap construction that the wear is quite rapid, thus requiring replacement within a matter of only several weeks from the time they are applied. Indeed, the cumulative cost of heel replacement may often exceed the original price of the shoes.

Numerous efforts have been made to design various types of heels in bizarre combinations and constructions but none have succeeded because of failure to realize that the remedy lies not in any special design, construction or quality of the heel but rather in the basic cause consequent upon the asymmetrical stress inherent in the physiologic nature of the dynamics of ambulation.

SUMMARY The present invention provides an improvement in a shoe wherein the top surface of the inner sole is provided with a local excavation in its postero-lateral aspect to accommodate the calcaneal projection. The local excavation is preferably filled with a resilient material such as rubber which can be flush with the top of the inner sole over the excavated area or project thereabove. The inner sole can also be provided with a separate secondary sole covering over the entire upper surface of the inner sole and excavated area with the resilient material filling.

DESCRIPTION OF THE DRAWING The present invention will be more fully understood from the following description taken in conjunction with the accompanying drawing wherein:

FIG. 1a is a vertical rear view of the human right leg;

FIGS. lb and 1c are right top and right lateral views, respectively, of the human right foot, FIG. 10 showing the calcaneum, the cuboid and the metatarsals 5, 4, 3, 2 and 1;

FIGS. 2a d are vertical cross-sectional views showing a conventional shoe construction (FIG. 2a) and shoe constructions according to the invention (FIGS. 2b d) wherein the calcaneum is shown in FIGS. 2a and d in vertical section along the line 22 in FIG. 1c;

FIG. 3 is a vertical sectional view through the long axis of the improved shoe construction according to the invention;

FIG. 4a is a top view of an inner sole according to the invention and FIGS. 4b e are side sectional views taken along line 4b of FIG. 4a;

FIG. 5 is a top view of an alternate embodiment of an inner sole construction according to the invention;

FIG. 6a is a top view of a further alternate embodiment of an inner sole and FIG. 6b is a sectional view taken along line 6b6b of FIG. 6a; and

FIG. 7a is a top view of another alternate embodiment of the invention and FIGS. 7b e are sectional views taken along line 7b7b of FIG. 7a.

DESCRIPTION A study of the anatomic structure of the lower extremity with special reference to the foot reveals that the vertical axis of the lower extremity in its posterior aspect starting with the center of the knee joint falls well inside the vertical axis of the calcaneus (FIG. 1a). Looking at the lateral aspect of the foot, the resultant stress along the calcaneus is downward and posteriorly (note arrows FIGS. 1a 0). Also, in the superior aspect of the foot, the longitudinal axis of the calcaneus indicates a resultant stress through the cuboid and the latera] tarsals (FIGS. lb and c).

In the act of walking the whole of the foot through its metatarsals and tarsals undergoes more or less uniform pressure. It is thus seen that the stresses on the foot are resolved into two dissimilar thrusts, namely, the asymmetrical pressure on the postero-lateral aspect of the foot and the relatively symmetrical pressure on the sole of the foot albeit with some emphasis on the lateral aspect of the foot. With the calcaneus touching the ground, the metatarsels through their mobility and that of the tarsals, fold down in a horizontal plane with the lateral aspect of the entire length of the foot acting as a hinge. While the foot rotates upon the hinge, the great toe first lands on the ground and is immediately followed by the rest of the foot thus completing the cycle. The arches, of course, yield resiliently with the movements. Now, with the foot solidly held to the ground by friction. the opposite foot performs the same cycle, etc., and ambulation continues with right and left foot alternating their respective movements. This cycle of ambulation is so obvious that any individual with normal anatomical conformation and gait can easily recognize the movements described. All one has to do is to walk very slowly and note these individual parts of the cycle.

This analysis suggests a new approach in the design of the shoe itself which would accommodate such movements from the standpoint of dynamic pressure and shock absorption. Once these physiological conditions are satisfied fatigue and excessive heel wear can be considerably minimized.

To accomplish this result, the most important approach is to provide in the inner sole 14 of the shoe 12 a localized hollow to accommodate the calcaneal projection 10. In this manner the calcaneum, upon pressure caused by the body weight, will fit into its specially provided niche 15 in the postero-lateral aspect of the shoes inner sole 14 instead of impinging upon a solid, hard surface such as obtains in the conventional I shoe (FIG. 2a). In addition to this calcaneal accommodation, there is provided a resilient material 18 interfaced in the niche 15, such as foam rubber or plastic of proper density or other material possessing such property. The top surface of this resilient material is made flush with (FIG. 3) or projecting above the top surface of the inner sole (FIG. 2c). Superimposed over the new entire upper surface of the sole is a layer of suitable material, Le, a secondary inner sole preferably resilient, giving the appearance of the top surface of the inner sole as that seen in the conventional shoe. Various alternative modifications of the top of the inner sole are as follows with reference to FIGS. 4 7:

In FIG. 4, the cutaway or excavation 15 shown in the postero-lateral aspect of the sole 14 may start as an oblique line making an angle with the long axis of the sole. This cutaway 15 may be wedge shaped (FIG. 4b) or a curved area (FIG. 40), a right angle cut (FIG. 4d) or an undercut (FIG. 42);

In FIG. 5, the cutaway may start as an arcuate line with cross-sections as in FIGS. 4!; e;

In FIGS. 6a and b, the cutaway 15 is complete; and

In FIG. 7, the cutaway is in the postero-lateral aspect of the sole l4 and may be in the form of a cup 15 with its side tapered so that its top diameter is greater than the bottom diameter (FIG. 712); FIG. 7c shows the cutaway 15 in the form of a concavity; FIG. 7d shows the cutaway 15 in the form of a cup with its top diameter same as the bottom diameter; and FIG. 7e shows the cutaway 15 in the form of a cup whose side is tapered so that its top diameter is less than the bottom diameter.

There are several alternate embodiments possible in the present invention without departing from the spirit and scope thereof. For example, in FIG. 3 the resilient portion 18 can be integral with the secondary sole 20. In other words, the secondary sole is provided with an integral resilient mass in its postero-lateral aspect, said integral mass coinciding with and corresponding to the local excavation 15.

In order to provide arch support, is is also possible to provide a shoe construction of the invention with a localized thickening of resilient material, for example on the underside of the secondary sole 20, approximately in the middle of the shoe transverse thereto to accommodate the transverse arch of the foot.

To accommodate persons of different weights, the local excavation 15 can be filled with a separable resilient mass 18 which can have varying densities depending on the weight of the wearer.

What is claimed is:

1. In a shoe the improvement which comprises a local excavation in the tip surface of the inner sole, in its postero-lateral aspect, to accommodate the calcaneal projection, said local excavation being filled with resilient material such as foam rubber which projects above the top surface of the inner sole.

2. Shoe of claim 1 which includes a separate secondary sole covering the entire surface of said inner sole.

3. Shoe of claim 2 having a resilient mass integral with the secondary sole in its postero-lateral aspect, coinciding with and corresponding to said local excavation.

4. Shoe of claim 2 wherein said secondary sole is provided with a localized thickening of resilient material on its underside approximately in the middle thereof transversely to accommodate the transverse arch of the foot.

5. Shoe of claim 1 wherein said local excavation is a wedge-shaped cutaway.

6. Shoe of claim 1 wherein said local excavation is an arcuate cutaway.

7. Shoe of claim 1 wherein said local excavation is a complete cutaway.

8. Shoe of claim 1 wherein said local excavation is cup shaped.

9. Shoe of claim 1 wherein said resilient material is a separable resilient mass of varying density for insertion into said local excavation. 

1. In a shoe the improvement which comprises a local excavation in the tip surface of the inner sole, in its postero-lateral aspect, to accommodate the calcaneal projection, said local excavation being filled with resilient material such as foam rubber which projects above the top surface of the inner sole.
 2. Shoe of claim 1 which includes a separate seconDary sole covering the entire surface of said inner sole.
 3. Shoe of claim 2 having a resilient mass integral with the secondary sole in its postero-lateral aspect, coinciding with and corresponding to said local excavation.
 4. Shoe of claim 2 wherein said secondary sole is provided with a localized thickening of resilient material on its underside approximately in the middle thereof transversely to accommodate the transverse arch of the foot.
 5. Shoe of claim 1 wherein said local excavation is a wedge-shaped cutaway.
 6. Shoe of claim 1 wherein said local excavation is an arcuate cutaway.
 7. Shoe of claim 1 wherein said local excavation is a complete cutaway.
 8. Shoe of claim 1 wherein said local excavation is cup shaped.
 9. Shoe of claim 1 wherein said resilient material is a separable resilient mass of varying density for insertion into said local excavation. 